Northern bald eagle

Ritz: Received on November 23, 1993 from a wildlife rehabilitator in Minnesota. Ritz could not be released back into the wild due to chronic problems with the growth of his feathers that leave him flightless for periods of time.

Glory: Received on June 8, 2004 from the National Aviary in Pittsburgh. Glory could not be released back into the wild due to a left wing injury.

Where to find me in the Zoo

Bald Eagle Exhibit

Fun Facts

Bald eagles construct the largest nest of all North American birds. Eagles are known to reuse nests for many years, both by same individuals as well as different individuals.

Bald eagles are able to tuck their wings and dive from above at incredible speeds. Some eagles can approach around 200 miles per hour in an attack on prey.

Eagles travel by soaring and gliding on thermals and can cover great distances without flapping their wings.

Bald eagles are fish eagles. They have spiny pads on the undersides of their talons to help keep wet, wriggling prey in place.

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Female bald eagles are larger than males. The bald eagle's body feathers are brown-black in color, and their head and tail is a brilliant white. They are fish eagles with powerful talons for seizing fish as they skim the surface of the water.

Longevity

Although it is not known for certain, northern bald eagles are estimated to live up to about 30 years in the wild. The oldest documented bald eagle in captivity was 47 years old.

Reproduction

Eagles mate for life and make excellent parents. They reach sexual maturity at 4-5 years. Their nests can be 5 feet wide and over 2 feet tall. These nests are made from sticks and are typically reused by adding more sticks to it each year. Females lay one to three eggs in these nests, and the chicks hatch after approximately 35 days of incubation. Both females and males care for the chicks and take turns in hunting and bringing back food back to their young. The young fledge from the nest at about 12 weeks of age.

Behavior

Eagles travel by soaring and gliding on thermals. They can cover great distances without flapping their wings. They have elaborate airborne courtship "dances," during which they perform a breathtaking display of diving, soaring, rolling and gyrating. Bald eagles are aggressive hunters but will often scavenge dead prey or even steal it from another bird when the opportunity arises.

Adaptations

The eagle's wing is light in weight but incredibly strong. They have powerful feet, sharp talons and spiny pads on the bottoms of their talons to snatch and grasp prey. The beak is curved and very powerful for tearing meat. The bald eagle's visual acuity is very high, but its night vision is poorly developed.

Size

Its body is 30-40 inches in length and its wingspan can be over 6 ft.

Weight

The northern bald eagle weighs 8-16 pounds.

Diet

In the wild, northern bald eagles eat fish, frogs, small mammals, insects, birds, carrion and occasionally snakes. This diet will vary seasonally depending on what is available. For instance, eagles will often eat a lot of carrion in the winter. In the Zoo, the northern bald eagle eats horsemeat, rats, chickens, bones, fish and quail.

Geographic Range

The northern bald eagle may be found in much of the contiguous United States, Alaska and Canada. While the northern subspecies is more numerous, the southern bald eagle subspecies can range as far south as northern Mexico.

Conservation at a Glance

North America: US, including Alaska, Canada and northern Mexico

In May, 2009, the Philadelphia Zoo, in partnership with the Pennsylvania Game Commision, placed an eagle chick hatched at the Zoo into an already established nest in Bucks County, Pennsylvania to be foster-reared.

Staff from PGC and the Zoo, along with the American Tower Corporation, which provided the necessary equipment, went up in a bucket lift to place the eaglet in the nest situated 50' off the ground in a communications tower.

This is the third such fostering involving an eaglet from the Philadelphia Zoo in the last 14 years.

Introducing captive-bred/born eaglets into the wild has an 80% success rate. In 1995, one captive-bred/born eaglet was successfully introduced into the wild in Massachusetts. In 1996, two captive-bred/born eaglets were successfully introduced into the wild of Pennsylvania. This "fostering" technique uses the genetic reservoir of captive populations to help reestablish viable populations in the wild.

The bald eagle was listed as a federally endangered species until 1995. The extensive use of the pesticide DDT in the mid-1900's resulted in the thinning of eggshells that would break during incubation or even prior to laying. In 1972 DDT was banned in the US. In 1980, there were only three bald eagle pairs in Pennsylvania. Due to the ban of pesticides and protection through the Endangered Species Act, the bald eagle has recovered and their population is much higher, though still not as high as they have been. In the 1700's there were possibly as many as 75,000 bald eagles living in the United States. When they were put on the endangered species list in 1967, there were only about 450 in the lower 48 states. Today, the eagle population has increased to about 10 times that amount. On July 4th, 1995, their status was upgraded to "threatened" and they were removed from the endangered species list on August 9, 2007.

To learn more about the conservation efforts at the Philadelphia Zoo, click here.